Diagnostic imaging methods include devices utilizing a variety of techniques such as X-ray, CT, ultrasonic, RI imaging, or MRI. Among them, MRI is the least harmful to the human body as compared with the other diagnostic imaging devices and forms images of the constituents in the human body. Hence, MRI is a very important device in clinical practice.
MRI devices can obtain tissue parameters such as spin density, T1, T2, chemical shift, magnetic transition, chemical exchange saturation transfer, blood flow, or spectroscopy which are unique information of the living body. Various biometric information images can also be obtained through such parameters.
Magnetic Resonance Angiography (MRA) is a method for measuring a blood flow in the arteries and veins of the human body using the MRI device and reconstituting the measured blood flow as an image. The MRA is currently providing clinical information which is very important for the diagnosis and treatment of vascular diseases. In the case of MRA imaging, there are various methods that utilize the properties of the blood flow rate, (i.e., TOF (time of flight)) using T1-weighted imaging of the blood flow.
Magnetic resonance angiography (MRA) imaging acquired by using an MRI device can measure the phenomenon caused by the blood flow through the blood vessels.
However, this connotes a probability that the blood flow rate can be changed by the vascular inner wall structure.
Furthermore, since X-Ray angiography inserts a catheter in the blood vessel and then administers a contrast agent, there is a fundamental problem in that the thickness of the blood vessel cannot be measured.
The thickness measurement of the brain vascular wall helps to objectively measure the progress of arteriosclerosis of a patient. As such, this can play a significant role in finding the causes of cerebral infarction and in the prevention of a future recurrence thereof. Therefore, there is a need for a method able to obtain an accurate thickness measurement of the vascular wall of the brain.
Current magnetic resonance imaging techniques for the vascular wall, which are used to observe the vascular wall, suppress the cerebrospinal fluid signal in the area through which blood flow pass and the area outside the blood vessel. Since the tunica media in the vascular inner wall has a dark signal if imaged with the magnetic resonance imaging system, conventional magnetic resonance imaging techniques for the vascular wall are not able to observe such a site. According to conventional techniques, only the thickness of the tunica adventitia can be measured and, consequently accurate vascular wall thickness cannot be measured. If the signal of the blood flow were to be separately obtained, together with a technique capable of imaging the tunica media site, it is expected that this would compensate for such disadvantages.
Accordingly, if it is possible to image both the vascular inner and outer walls to automatically divide them, it is possible to obtain an accurate vascular wall size. Also, it is possible to accurately measure the thicknesses between the inner and outer walls and thus, greater stability of a stent used in all sites (brain, heart, lower limb, etc.) of the human body can be obtained by selecting and using a stent with an accurate size, even upon operation of the stent in the blood vessel.